Infobip Dev Days 2015

Here are my notes from an awesome 4th Infobip Dev Days 2015 conference:



  • Presenter: Izabel Jelenić, Co-founder, CTO
  • infobip – 600+ employees (122 devs)
  • Worldwide A2P SMS traffic is expected to grow. Revenue > 45bn.
  • They handle 150M transactions daily.
  • They said they’re doing business with “one big social” network, but they didn’t name it actually, I wonder why is that (some kind of NDA or what? 🙂)
  • Picture time:

How we ended up doing continuous delivery

  • Presenter: Mario Žagar, Senior Software Architect
  • ASAP and as often we have to go into production
  • Unit & integration tests
  • Scaling cube
  • First they scaled by increasing monoliths
  • Then they took some parts out of the monolith (API, Billing, Inbound SMS, …) => easier to focus, possible to deploy independently
  • Typical feature deployment today:
    • Short lived feature branches with Git
    • Develop & run tests locally
    • Push feature branch to remote repository (Stash)
    • Jenkins – CI server builds the feature branch
    • Deployment artifacts published to Infobip repository (Artifactory)
    • Deploy feature branch to integration environment
    • Run tests on integration environment
    • Merge pull request to master branch & release
  • Average about 80 deploys per day
  • DevOps culture – you built it, you deploy it, you support it
  • Troubleshooting tools:
  • Picture time:
  • And a few more here, since, well, you know I love MEMEs:

Scrum experience

  • Presenter: Marko Stipanov, Product Owner
  • How to increase productivity?
    • hiring more devs?
    • best is to hire someone new and give them some totally new project
  • PDD – Panic Driven Development
    • the bigger the panic the greater priority
    • how relates to this, please hands up hand_rock_n_roll
  • they tried with daily report writing
  • Agile process manifesto
  • they divided their 60 devs at a time to 12 teams and each team works on a small project
  • Product Owner
    • vision and definition of products
    • goal setting
    • priority setting of the whole team
    • talks to stakeholders
  • Scrum ceremonies
    • organisation
    • iterative process
  • Scrum steps (they do the sprints fro 1-2 weeks instead of 2-4):
    • Product backlog
    • Sprint backlog
    • SPRINT
    • Deliverable
  • 1 project = 1 team
  • 1 team => more projects
  • Priorities are defined by business value
  • Kanban, Scrumban
  • Daily team lead meeting with just few minutes
  • You can’t do agile without teams!
  • Scrum definitely give us a better intercommunication.
  • Picture time:

Modern SQL

  • Presenter: Markus Winand, SQL expert and author
  • SQL 99 broke the relational standard
      • “for each” loop of SQL
    • WITH
      • “private methods” of SQL
      • “while” loop of SQL
  • SQL 2003
    • Turing complete
      SELECT dep, salary, SUM(salary) OVER (PARTITION BY dep) FROM ...
    • OVER and GROUP BY
      • actually, do this in the application, thank you very much
  • SQL 2008
    • SELECT TOP is not official – it’s FETCH FIRST ROWS ONLY
  • SQL 2011

Indexes: The neglected performance all-rounder

  • Presenter: Markus Winand, SQL expert and author
  • 50% SQL problems are caused by poor query/indexing
  • CREATE INDEX is not in the standard!
  • The solution- indexing is a development task!
  •  And now the author hits the spots when he explains that in
    • 11 SQL books he analyzed only 1% of the pages are about indexes
    • 14 database administration books he analyzed only 6% of the pages are about indexes
  • Everybody knows indexing is important for performance, yet nobody takes the time to learn and apply it properly.

Personal and Interpersonal Effectiveness

  • Presenter: Danilo Goliani, PhD professor, enterpreneur
  • Our clients are paying our paychecks!
  • Personal effectiveness – others have faith in me
  • Team effectiveness – I have faith in others
  • Organisational effectiveness – clients love us
  • Stephen R. Covey: 7 Habits of Highly Effective People
  • Courage – willingness and ability to express your thoughts and emotions
  • Don’t just say NO to your children – explain also WHY
  • Self induced interrupt
  • Brain Games
  • Picture time:

Machine learning

Java puzzlers

  • Presenter: Aleksandar Dostić, Senior Software Engineer IB
  • Picture time intro:
  • Puzzle 1:
  • Puzzle 2:
  • Puzzle 3:
  • Puzzle 4:
  • Puzzle 5 – the most sneaky one!
    and here is why!!! shockedjava_5_explanation

HA-JDNI as a Solution for Service Discovery in Distributed Systems

  • Presenter: Aleksandar Branjković, Head of Mobile Payments R&D
  • Picture time:



Written by Nikola Brežnjak